• Proceedings of the Technology Innovation Conference
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• 1996.12a
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• pp.63-76
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• 1996

This study investigates the factors determining accounting method for R & D costs (capitalize vs. expense) in Korea. Using agency theory and other economic factors, probit and regression models have been developed to distinguish between firms choosing different accounting alternatives for R&D costs. The results are consistent to debt contract, R&D burden and regulation hypotheses both in probit and regression analysis. The size variable has opposite sign in univariate t-test and probit analysis but the signs are mixed and insignificant in regression which may be due to the differences of political environment between Korea and the US. Generally, the results are consistent to those of previous research. The results support the hypothesis that firms with higher leverage and larger burden of R&D costs are more likely to capitalize R&D costs. Partially, larger and regulated firms are more likely to expense R & D costs.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.243-248
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• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.51-58
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• 2011

The objective of this study is to identify whether or not the ground water level is decreasing. We suggest a method of estimating the change in groundwater level using newly developed groundwater pumping station data. The Goseong area located in Gyeongnam province was selected considering three factors. First, this area demands relatively large amount of irrigation water because most of the land is used as a paddy field and the proportion of the paddy field within total arable land is increasing. Second, groundwater level data in nearby area are available since these are monitored by Water Management Information System (WAMIS). Third, many groundwater pumping stations have been developed in this area in order to overcome droughts thus detail information for pumping stations are available. Regression results indicate groundwater level has been decreased for over 20 years. This decreasing trend is due to the shortage of surface irrigation water which was caused by the decrease in rainfall.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1775-1776
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• 2006

This paper deals with the problem of friction measurement of an inverted pendulum system using the regression analysis and proposes a solution. The approach taken in this study is getting the friction from a regression relational expression between the motor voltage and the cart velocity of an inverted pendulum system. The result to compensate LQR (linear Quadratic Regulator) controller with the friction which is measured in system, improved the performance of the system. Above all, the study has found that the proposed compensation of the friction reduces the oscillation of the cart position. In conclusion, the proposed method is useful when parameters in the given system model are not known.

• Applied Microscopy
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• v.41 no.1
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• pp.75-79
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• 2011

For quantitative analysis of nano-crystal structure, we reported the accuracy improvement method of lattice parameters measured from electron diffraction. For calculation of Au lattice parameters used as a standard crystal structure, it was considered two different acquisition methods (detector and enegy-filter) and three different calculation methods (conventional, least-square and regression fit). As a result, the measurement reliability could be enhanced by using CCD camera which gives higher performance, while energy-filtering did not affect the improvement the camera constant accuracy. Also, the accuracy of lattice parameters could be improved up to $10^{-4}$ order by regression fitting with correction formula. Finally, it is expected that the combination of regression fitting and intensity extraction from energy-filtered precession electron diffraction gives a solution of quantitative structure analysis for unknown nano-crystals.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.118-128
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• 2012

An attempt is given to the problem of analyzing the two-way binary attribute data using the logistic regression model in order to find a sound statistical methodology. It is demonstrated that the analysis of variance (ANOVA) may not be good enough, especially for the case that the proportion is very low or high. The logistic transformation of proportion data could be a help, but not sound in the statistical sense. Meanwhile, the adoption of generalized least squares (GLS) method entails much to estimate the variance-covariance matrix. On the other hand, the logistic regression methodology provides sound statistical means in estimating related confidence intervals and testing the significance of model parameters. Based on simulated data, the efficiencies of estimates are ensured with a view to demonstrate the usefulness of the methodology.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.579-583
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• 2006

The purpose of this paper is to study a relationship between alliance success factors and performances of strategic alliance. In order to achieve the purpose of this research, factor analysis, reliability and validity and regression method are used. In conclusion, alliance success factors can be divided as mutual complementarity and information sharing factor, sharing and mutual agreement of vision and goal factor, performance management factor and culture and organization factor. According to regression results, all of four factors affects significantly dependent variables. Among them, mutual complementarity and information sharing mostly affects each dependent variable.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.357-373
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• 2013

In this paper, a back analysis program for analyzing the behavior of tunnel-ground system and evaluating the material properties and tunnel design parameters was developed. This program was designed to be able to implement the back analysis of underground structure by combination of using FLAC and optimized algorithm as direct method. In particular, Rosenbrock method which is able to do direct search without obtaining differential coefficient was adopted for the back analysis algorithm among optimization methods. This back analysis program was applied to the site to evaluate the design parameters. The back analysis was carried out using field measurement results from 5 sites. In the course of back analysis, nonlinear regression analysis was carried out to identify the optimum function of the measured ground displacement. Exponential function and fractional function were used for the regression analysis and total displacement calculated by optimum function was used as the back analysis input data. As a result, displacement recalculated through the back analysis using measured displacement of the structure showed 4.5% of error factor comparing to the measured data. Hence, the program developed in this study proved to be effectively applicable to tunnel analysis.

• Journal of Multimedia Information System
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• v.3 no.2
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• pp.9-12
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• 2016

This paper is concerned with the effective and efficient identification of the gender and motion of humans. Tracking this nonverbal behavior is useful for providing clues about the interaction of different types of people and their exact motion. This system can also be useful for security in different places or for monitoring patients in hospital and many more applications. Here we describe a novel method of determining identity using machine learning with Microsoft Kinect. This method minimizes the fitting or overlapping error between an ellipsoid based skeleton.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.374-386
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• 2024

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.